Amalgam mixing capsule



Jan. 18, 1966 C. J. THIEL ETAL AMALGAM MIXING CAPSULE Filed May 29, 1963 M IUHIW mm 36 -33- M INVENT R W United States Patent "ice 3,229,963 AMALGAM MIXING CAPSULE Charles J. Thiel, 625 6th Ave., and Louis J. Michaels, 1210 6th Ave., both of Dayton, Ky. Filed May 29, 1963, Ser. No. 284,249 8 Claims. (Cl. 259-29) This invention relates to apparatus for agitating and dispensing and more particularly the invention is directed to apparatus for the preparation and application of amalgam in the field of dentistry. The invention relates to improvements in the apparatus described in our co-pending application Serial No. 145,878 filed August 18, 1961.

Our earlier application discloses apparatus in which the amalgam forming constituents (mercury and an alloy usually containing silver) are introduced into a capsule, are agitated in that capsule and are automatically dispensed from that capsule into a tube from which the amalgam can be dispensed into a tooth cavity. The objective of the invention there is to provide for the rapid preparation of the amalgam and the introduction of it into that type of container from which it can be immediately discharged into a tooth cavity without requiring intermediate handling steps and particularly without requiring contact of the amalgam by human hands.

One of the important elements or combination of elements in that invention is the capsule within which the amalgam is mixed. The capsule provides an elongated chamber into which the amalgam forming constituents are introduced. The capsule has at one end a valved discharge orifice which is in communication with a tube into which the amalgam is discharged after it has been mixed. A pestle is freely disposed in the capsule chamher and is of considerably smaller dimension than the capsule chamber so that when the capsule is vibrated, the pestle will reciprocate within the chamber to perform two functions. During a first period the pestle mixes the amalgam forming constituents to form the amalgam. Thereafter the valve is opened and the pestle drives the amalgam through the valved discharge orifice and to a receptacle which may be in communication with the orifice.

The object of this present invention has been to improve the efficiency of the agitator and dispenser of the earlier application the improvement arising particularly through a new design of the capsule chamber. To this end the invention provides for a stepped configuration of the chamber which forms a shoulder intermediate the ends of the chamber. Through experience with this configuration we have found that the amalgam is more rapidly and more thoroughly discharged from the capsule through the discharge orifice.

The shoulder capsule is not only advantageous in use with the invention of our earlier application, but addi tionally has the advantages when used in capsules which were known prior to our invention. The prior capsules had no provision for discharging amalgam other than the opening of the capsule by separating it into its two halves and shaking the amalgam on to some suitable surface. By interposing a shoulder intermediate the ends of that capsule the mixed amalgam is caused to move entirely into one end of the capsule, the other end being cleaned by the reciprocatory movement of the pestle so that the amalgam can be removed from the capsule merely by emptying one section rather than two.

It has been another objective of the invention to provide for the proper relationship of the size, weight and materials used in the pestle, all in respect to the dimension and configuration of the capsule chamber.

These and other objectives of the invention will become more readily apparent from the following detailed 3,229,963 Patented Jan. 18, 1966 description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a side elevational view of apparatus employing the invention, and

FIG. 2 is a side elevational view, partly in section, illustrating the capsule of the invention.

The capsule of the present invention is illustrated at 10 and is mounted in apparatus by which the capsule can be rapidly vibrated. That apparatus has been described in our co-pending application, Serial No. 145,- 878, and need be described only in broad outline here. The capsule is mounted between arms 11 and 12, the arms being connected to a drive shaft 13 of a motor 14 in such a manner that upon energization of the motor the arms are caused to vibrate rapidly back and forth, that is, toward the left and right as viewed in FIGURE 1. The arm 12carries an operator 15 which is connected to a valve 17 in one end of the capsule. The operator 15 is caused by a cam 18 to slide upwardly to open the valve 17, the cam 18 being operably connected to a timer 19.

The capsule carries, at the valved end thereof, receptacle 21 which is in the form of a tube adapted to receive the amalgam after it has been mixed within the capsule.

Referring more particularly to FIGURE 2, the capsule comprises a first casing part 25 which is closed at one end by an end wall 26. At the open end of the first casing part 25 there is a tapered male surface 27 which forms a spigot connection with a similarly tapered female surface 28 at the open end of a second casing part 29. The second casing part has a discharge orifice 30 communicating with a receptacle 21. The valve 17 is embodied in the discharge orifice to open or close it as required by the operation of the invention.

The internal transverse dimension of the first casing part is smaller than the internal transverse dimension of the second casing part thereby providing a shoulder 34 intermediate the ends of the chamber 33 which is formed when the two casing parts are joined together, that shoulder does not have to be formed at the intersection of the casing parts, that is, it could be formed integrally with either part, preferably the first part .25. A pestle '35 is disposed within a chamber33, the :pestle providing the agitating medium by which the amalgam forming constituents are mixed.

For clarity, the capsule will be described as having a forward end 37, which is the discharge end, and a rearward end ;38 which is the opposite end. The lengthtof the pestle 35 is preferably smaller than-the distance be tween the shoulder 34 and the rearward end of the chamber 33 and is preferably longer than the distance between the shoulder 34 and the forward end of the discharge chamber 33. This relationship provides assurance that the forward end of the pestle will properly clear the first casing part during its reciprocatory motion and that the rearward end of the pestle will not be caught on the shoulder 34 during the vibration of the capsule. Further, the relationship provides a sufficient distance for the movement of the pestle within the chamber 33 to effect the mixing of the amalgam.

The following dimensions of the elements are provided to facilitate complete comprehension of the invention but it is to be understood that they are not intended to place limits on the invention except as otherwisefindicated.

The chamber 33 is cylindrical and .its smaller diameter is approximately 0.360 inch. Its larger diameter is approximately O.375 inch thereby providing a shoulder 34 between the two casing parts of approximately 0.0075 inch. The forward end wall of the chamber 33 is a .frusto conical, the elements defining it converging at angle which may be approximately 150. The chamber 33 is approximately one inch long with the distance between the shoulder 34 and the rearward of chamber 33 being approximately inch long. The capsule is preferably made of nylon because of its resistance to abrasion and because the amalgam does not easily adhere to it.

The pestle 35 is preferably 0.360 inch long and inch in diameter. It may be formed as shown in any of the several embodiments in our co-pending application referred to above but preferably is as illustrated in FIG- URE 2 and is constituted by a stainless steel core 40 surrounded by a nylon sleeve 41. The nylon sleeve prevents any contact of the interior walls of the capsule by the stainless steel core and thereby preserves the smooth interior of the capsule which is important to its cleaning action. The stainless steel core, on the other hand, is important in order to give to the pestle the proper weight for the efiicient agitating and mixing action. The weight of the pestle may vary within the range of 20-60 grains with the forty grain pestle being preferred. The heavier pestles are used to mix the dryer amalgam in which the weight of the mercury is approximately equal to the weight of the alloy. As the percentage of mercury by weight increases, the weight of the pestle may be decreased.

In the operation of the invention the casing parts forming the capsule are separated and the amalgam forming constituents are introduced along with the pestle 35. The capsule is closed by telescoping the first casing in part 25 into the, second casing part 29 and mounting the capsule between the arms 11 and 12 of the agitating apparatus. If a capsule which does not have the discharge orifice of our earlier invention is used, the capsule is agitated for a few seconds until the amalgam is mixed. The capsule is then removed from the agitating apparatus and opened. The mixed amalgam will be found in the casing part 29, the casing part 25 having been thoroughly cleaned by the movement of the pestle. An amalgam can then be deposited on any suitable surface.

If a capsule of the type described in our earlier invention, that is, one having a valved discharge orifice in the forward end, the capsule is filled and placed at the agitating apparatus as before. The capsule is agitated in that apparatus for a predetermined period of .timewhereupon the valve 17 is opened and the vibrating ofthe capsule continued. In a short time, less than five seconds, the pestle will drive the amalgam into the receptacle 21 from which it may be directly applied to the tooth of a patient.

What is claimed is:

1. An amalgam mixing device comprising a capsule having an elongated mixing chamber,

said capsule having a rearward section of smaller transverse dimension than that of a forward section thereby forming a shoulderintermediate the ends of said chamber, said forward section having a valved orifice in its end, and a pestle in said chamber.

2. An amalgam mixing device comprising a capsule having an elongated mixing chamber,

said capsule having a valved orifice at the forward end thereof,

said chamber having a rearward section of smaller transverse dimension than that of the forward section thereby forming a' shoulder intermediate the ends of said chamber,

and a pestle in said chamber having a longitudinal dimension less than the length of said rearward section.

3. An amalgam mixing device comprising a capsule having an elongated mixing chamber,

said capsule having a valved orifice at the forward end thereof,

said chamber having a rearward section of smaller transverse dimension than that of the forward section thereby forming a shoulder intermediate the ends of said chamber,

and a pestle in said chamberhaving a longitudinal dimension less than the length of said rearward section, and greater than the length of the forward section.

4. An amalgam mixing device comprising a first casing part having an internal bore which is closed at one end,

a second casing part having an internal bore which is normally closed at one end,

means joining said casing parts together to form a normally closed mixing chamber,

the transverse dimension of the first bore being smaller 1 than the transverse dimension of the second bore. thereby providing a shoulder at the joint between the two casing parts,

a valved discharge orifice inthe end of, the second casing part,

and a pestle movably mounted in said chamber.

5. An amalgam mixing device comprising,

a first casing part having an internal bore which is closed at one end,

a second casing part having an internal bore which is normally closed at one end,

means joining said casing parts together to form a normally closed mixing chamber,

the transverse dimension of the first bore being smaller than the transverse dimensionof the second bore thereby providing a shoulder of approximately .10 mils at the joint between the two casing parts,

a valved discharge orifice in the end of the second casing part, and

a pestle movably mounted in said chamber.

6. In a capsule having a valved orifice at one end,

a pestle for mixing amalgam and driving it through said orifice,

said pestle comprising: i

a metallic core, and a nylon jacket surrounding :said metallic core, said pestle weighing approximately 20-60 grains, being 0.360 inch long and 0.314 inch in diameter.

7. In a capsule having a valved orifice at one end,

a pestle for mixing amalgam and driving it through said orifice,

said pestle comprising:

a metallic core, and a nylon jacket surrounding said metallic core, said pestle weighing approximately 20-60 grains 8.In a capsule having a cylindrical mixing chamber;

of 0.375 inch diameter and approximately one inch length, and having a valved orifice at one end, a pestle for mixing amalgam in said chamber and driving it through said orifice, said pestle comprising;

a cylindrical member weighing 20-60 grains and having approximately 0.314 inch diameter and approximately 0.360 inchlength.

References Cited by the Examiner UNITED STATES PATENTS 2,072,026 2/ 1937 Cline 222 -554 2,524,523 10/ 1950 Greenberg 259-72 2,580,132 12/ 1951 Seymour 25929 1 2,678,196 5/1954 Bear 259 -144 2,710,742 6/1955 Vlock 259-75 1 2,774,580 12/ 1956 OBrien 259144 3,034,735 5/ 1962 Cadwell 241-184 3,087,707 4/1963 Moonan 259-29 CHARLES A. WILLMUTH, Primary Examiner.

GEORGE I. NORTH, Examiner. 

1. AN AMALGAM MIXING DEVICE COMPRISING A CAPSULE HAVING AN ELONGATED MIXING CHAMBER, SAID CAPSULE HAVING A REARWAED SECTION OF SMALLER TRANSVERSE DIMENSION THAN THAT OF A FORWARD SECTION THEREBY FORMING A SHOULDER INTERMDIATE THE ENDS OF SAID CHAMBER, SAID FORWARD SECTION HAVING A VALVED ORIFICE IN ITS END, AND A PESTLE IN SAID CHAMBER. 